U.S. regulators probing dietary supplements, besides ephedra

Last Updated: 2004-01-21 12:52:30 -0400 (Reuters Health)

By Lisa Richwine

WASHINGTON (Reuters) - U.S. regulators who decided to ban the weight-loss herb ephedra are studying whether other dietary supplements are too dangerous to be sold, the head of the Food and Drug Administration said on Tuesday.

FDA Commissioner Mark McClellan singled out bitter orange, aristolochic acid and usnic acid as ingredients under increased scrutiny. All have been used in supplements promoted for weight loss.

The FDA warned consumers in April 2001 that aristolochic acid had been linked with kidney damage, but some supplements on the market may still contain the ingredient, McClellan said. In November 2001 the agency warned that usnic acid may lead to serious liver toxicity.

"While most supplements are probably safe in the dose people take them, we are concerned about a number of other dietary supplements that are currently on the market," McClellan said during a speech at the University of Mississippi.

"We will be doing more work in the coming months to more closely evaluate the potential safety risk of these products, and we could take further action to remove unsafe dietary supplements from the market," McClellan added.

Michael McGuffin, president of the American Herbal Products Association, said the industry welcomes closer FDA oversight, hoping it will help boost public confidence in supplements.

"We don't want to be ignored. We want the agency to be activist. We want the bad players removed," McGuffin said.

Makers of dietary supplements such as vitamins, herbs and minerals do not have to prove the products are safe and effective before they can be sold. The government must show a supplement presents an "unreasonable" risk to order it off the market.

The FDA last month said it would ban ephedra, an herbal stimulant, after determining it was linked to heart attacks, strokes and deaths. Ephedra makers insist the herb is safe when used as directed.

The ban will take effect 60 days after the FDA publishes its final rule on ephedra. The rule may be released as early as next week, a senior FDA official said.

Industry groups said they agreed aristolochic acid can be toxic and already had called for removal of the ingredient in dietary supplements.

The Council for Responsible Nutrition, which represents supplement makers, supports additional study of usnic acid and bitter orange, said John Hathcock, vice president of scientific and international affairs.

"We would always support more research," Hathcock said.

Bitter orange is chemically similar to ephedra but has weaker biological activity and "ought to be safer" than ephedra, Hathcock said.


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